The Lion software mimics some of the features of the iPhone and iPad interface.

The company has a reputation for being conservative with its forecasts.

Shares jumped 5.3% in extended after-hours trading to their highest for a year.

Battles

The price had suffered after its founder and Chief Executive, Steve Jobs, took a long-term break last January for medical reasons.

The future stewardship of the company remains an open question. On Tuesday the Wall Street Journal was reporting that several Apple board members had discussed a successor to Mr Jobs, and had talked about the matter with at least one head of a high-profile tech company.

Another uncertainty for the company is a web of patent battles with rivals.

It claims Taiwanese rival HTC has infringed its patents, with HTC claiming a number of infringements against Apple.

Apple is also in dispute over the rights to technology with South Korea's Samsung and US competitor Motorola.